Myth #4: Sports drinks can help you exercise more safely and effectively.

Truth: Sports drinks contain two main ingredients that are theoretically beneficial for exercisers: sodium, which helps the body retain water, and sugar, which the body burns for energy. But very few people exercise hard enough to sweat away much sodium or to use up their carbohydrate reserves, which the body converts to sugar. You'd have to jog for at least two hours, for example, before your carbohydrate stores would start to run low. So unless you're doing a marathon or other exhaustive exercise, plain water is all you need.